Hello, McFly!

Here is a whistle stop summary of building the Pi powered Delorean Time Circuit and Flux Capacitor

  1. Wire 3 red LED common anode 7-segment displays to an Adafruit HT16K33 LED backpack.  Set its I2C address as 0x70
  2. Repeat for green and yellow (0x71, 0x72 respectively)
  3. Build and connect the flux capacitor to the “yellow” backpack
  4. Connect all three to the 3v3, SDA, and SCL headers accordingly (pins 1, 3, and 5 on the GPIO – don’t forget to connect a ground as well)
  5. Make sure the I2C bus is setup on your Pi
  6. Download my Python code.  You may need the AdaFruit I2C and LEDBackpack libraries if you don’t have them already.
  7. Tweak the Python as needed and execute the code!

Optional extras

  1. Put it in a box and label accordingly
  2. Don a white lab coat and a wig

2 thoughts on “Hello, McFly!

  1. Alan S

    Hello – taken my days to figure out I had the same combination of common anode and backpack that wouldn’t work! Your code looks like the very thing I need but when i try it on the ex_7segmentclock.py demo with your class substituted in I get an

    AttributeError: LEDBackpack instance has no attribute ‘getBufferRow’

    what am i doing wrong?

    1. ForToffee

      Without seeing your code I can’t be sure. I have updated the zip to now include the two Adafruit classes (LEDBackpack and I2C) that I used with the project. I can’t check your example at the moment as I don’t have a 7seg wired up, but will have a look later if I can.


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